1. Field of the Invention
The present invention relates to a substrate position detection apparatus that detects a position of a substrate housed in a semiconductor device fabrication apparatus and the like, a film deposition apparatus equipped with the substrate position detection apparatus, and a substrate position detection method.
2. Description of the Related Art
In a semiconductor device fabrication process, a substrate is transferred into various fabrication apparatuses including a film deposition apparatus, an etching apparatus, an inspection apparatus and the like, and undergoes corresponding processes. The substrate is transferred into the fabrication apparatuses by a transfer arm having a fork or an end effector. The substrate transferred by the transfer arm has to be accurately positioned in a predetermined position. For example, when the substrate deviates from the predetermined position, the substrate cannot be uniformly heated, thereby degrading uniformity in film thickness and/or film properties. In addition, such deviation may cause a problem in that the substrate cannot be taken away by the fork or an end effector.
Moreover, among some molecular layer deposition (MLD) apparatuses, which have attracted much attention because of their thickness controllability and uniformity, there is an MLD apparatus where a substrate is rotated at relatively high speed so that reaction gases are alternately adsorbed, instead of alternately supplying the reaction gases. In such an apparatus, the substrate may be ejected by the rotation if the substrate is not in a predetermined place.
In order to solve such problems by accurately arranging the substrates in predetermined positions, there is proposed a method in which a charge coupled device (CCD) camera or the like is used to take an image of the substrate, thereby detecting the position of the substrate in accordance with the image (see Patent Document 1). According to this method, because an image of not only the substrate but also a susceptor can be taken by one CCD camera, an optical system can be simplified, which is advantageous in terms of reduced costs, and a remote detection can be realized.
Patent document 1: Japanese Patent Application Laid-Open Publication No. 2010-153769.